The merits of Representative Ryan are obvious to anyone paying attention to his endeavors, especially in the past three years, in which he has emerged as a leading voice countering the president's fiscal flim-flammery, which has plunged the country ever further into ruinous debt. Conservatives cheered when Ryan reduced Barack Obama to stumbling deferrals at the February 2010 healthcare summit, with direct and aggressive questions rooted in the fiscal data which the Wisconsin congressman has long since mastered.

If one accepts the contention that the great crisis of American governance is really a crisis of entitlements and their funding, then Paul Ryan has been at the forefront of the effort to craft serious solutions. And it's a pity the House Democrats have resolutely refused to join him in it.

But there's a reason they don't, and it's not simply their reflexive preference for those programs and their excesses. Ryan's collected ideas for meaningful reform constitute both the 2012 and 2013 House Republican-proposed federal budgets. Known collectively as the "Ryan plan", they poll consistently poorly, managing at best a break-even point in some polls, depending on public attention and circumstance. (For example, Public Policy Polling last year found it losing by 16 points in Florida, and 23 in North Carolina.)

Whatever the Ryan plan's objective merits – and they are considerable, and considerably better than anything the president has to offer – this is the ground truth: it's unpopular. And the Republican House that puts it forth is even less popular, clocking in at a mere 17.2% approval in the latest RealClearPolitics average.

This brings us to the considerable peril for the Romney effort inherent in the Ryan pick. Every re-election effort is a referendum on the incumbent, but hitherto, the only incumbent in play was Barack Obama. Now, there's another: Paul Ryan and the Republican House. Democrats who had to defend the lackluster governance of the Obama years are now given the superb gift of a man who arguably shares blame for them. The contention that Paul Ryan is as responsible for the failures of the Obama administration as Obama himself is deeply preposterous, of course – but that doesn't mean the Democratic campaign won't make it. And given the outcomes of past confrontations between this Congress and this White House, there's a good chance it will work.

Consider, too, the core value proposition of the Romney campaign: actuarial competence, business acumen, and sound management. Paul Ryan accentuates all these. And that's the problem: he amplifies the existing Romney sales case, rather than expands it. As it happens, Ryan is also a solid social conservative: a faithful Catholic and family man. Whether he'll be allowed to make that appeal in coming months, in a campaign that has shown no appetite for it, remains to be seen.

Finally, note that the Republican presidential nominee, the one man in America who cannot credibly attack the president on Obamacare, has chosen a man who voted for Tarp. In fairness, that's a lot of people: but don't expect Team Obama to fail to note it.

Mitt Romney, with this pick, has decided to run not on his own record and his ideas, but on those of Paul Ryan and the Republican House in which Ryan has been an intellectual and animating force. Like the genius of acquisition he used to be, he identified external assets and grabbed them.

In a sense, given the paucity of his own ideas and narrative, it's a good move. But it highlights exactly that deficiency, and the assets come with tremendous liabilities. In Paul Ryan, Republicans now have a man who would make an intellectually forceful and coherent vice-president – surely a welcome change from the hapless nonentity that is Joe Biden. But they also have a man who brings great danger to the ticket's electoral proposition. In that light, it's a Hail Mary pass – when all that was needed was to advance the ball five yards.